Fastener-applying device



Dec 5,. 1939. A. H. MAYNARD ET AL.

FASTENER-APPLYING DEVICE Filed July 9I 1938 2 Sheets-Sheet l zahlr Dec. 5, 1939. A. H. MAYNARD ET Al. 2,181,904.

FAsTENER-APPLYING DEVICE Filed July 9, 1938 2 Sheets-Sheet 2 Patented Dec. 5, 1939 UNITED STATE FATNT OFFI FAS'EENER-APPLYING DEVICE Arthur H. Maynard, Warwick, and Joseph Gambao, East Greenwich, B.. I., assignors to Boston Wire Stitcher Company, Warwick, R. I.,

a corporation of Maine Application July 9, 1938, Serial No. 218,358

7 Claims.

One object of the invention is to provide an implement of the type indicated adapted to rock the legs ofv a staple into parallel relation to its laf crossbar without deformation intermediate their ends to form a at stitch.

Another object of the invention is to provide an implement of the type indicated wherein the stapling arm is held in raised position with respect to the work until a staple is driven to penetrate its legs through the work and thereafter moved toward the work to engage the ends of the projecting legs of the staple with camming grooves on the base of the implement.

Another object of the invention is to provide an implement of the type indicated having a sliding anvil with selective camming grooves formed therein for eiecting a nat permanent Astitch or a temporary pin-stitch.

Still another object of the invention is to provide an implement of the type indicated ywhich is of simple and compact construction and proof against derangement or getting out of order.

Furtherobjects of the invention are set forth in the following specification which describes one form oi construction of the implement, by way of example, as illustrated by the accompanying drawings'. In the drawings:

Fig. l is a side elevational view of a wellknown type of implement incorporating the novel features of the present invention;

Fig. 2 is a part-sectional view similar to Fig. l showing the anvil yieldingly heldin one of its two operative positions on the base to form a pin-stitch and the hand-lever depressed to drive a staple While the stapling arm is held in raised position with respect to the work;

Fig. 3 is a part sectional View similar to Fig. 2 showing the stapling arm depressed into engagement with the work to cause the legs or the driven staple to be clinched;

Fig. 4 is a front view of the implement with the parts shown in the same position as illustrated in Fig. 1;

Fig. 5 is a transverse sectional View taken on line 5 5 of Fig. 2 and showing the legs of the driven staple projecting from the stapling arm while the latter is held in raised position with respect to the work;

Fig. 6 is a View similar to Fig. 5 showing the legs of the staple being rocked outwardly by the camming grooves in the anvil as the stapling arm is ino-ved toward the base;

Fig. '7 is a view similar to Fig. 5 showing the stapling arm moved into engagement with the work and the legs of the staple rocked outwardly through an arc of ninety degrees to form a iiat pin-stitch in the work;

Fig. 8 is a longitudinal sectional View through the clinching anvil and base of the implement m showing the anvil yieldingly held in another operative position to aline a different set of clinchergrooves with the staple being driven;

Fig. 9 is a view similar to Fig. 6 showing the ends of the legs of a staple rocked inwardly by the camming grooves on the anvil as the stapling arm is moved toward the base;

Fig. 10 is a view similar to Fig. 9 showing the stapling arm moved into engagement with the worl. and the legs of the staple clinched in parallel relation to its crossbar to form a flat permanent stitch;`

Fig. 1l is a transverse sectional view taken on line Il-I of Fig. 8 showing the spring means for yieldingly holding the anvil in different positions on the base; and

Fig. l2 is a perspective view of the forward end of the base and anvil showing the structure of the parts to adapt the anvil to be detachably mounted on the base.

A standard type of desk stapler has a stapling arm embodying a magazine for the staples pivotally mounted on a base and staple-applying mechanism'at the end of the arm adapted to cooperate with an anvil on the base. type of implement a spring is provided ior holding the stapling arm raised with respect to the base to permit the work to be inserted therebetween. When the implement is operated the spring yields to permit the arm to rst move toward the base to grip the worl; thereagainst and the driver is thereafter operated to drive a staple. As the staple is driven the ends of the legs are engaged by clincher-grooves in an anvil on the base and the clincher-grooves act to continuously bend and clinch the legs as they are driven. g

It has heretofore been proposed to provide a device for first driving a staple through .the work and thereafter rocking its straight projecting legs outwardly to form a iiat stitch, but such previously used implements require special clinching means or other elements to cause the legs to be folded without deformation. In the Maynard United States Patent No. 1,506,073, is-

wim this 3 sued August 26, 1924, an arched spring-plate is mounted on the base and overlies the clinching anvil to hold the work suspended above the anvil until a staple is driven therethrough. After the staple has been driven the force applied causes the spring-plate to yield to engage the ends of the staple-legs with camming grooves in the clincher-anvil. In the pending application of John F. Cavanagh, Serial No. 110,364, filed November 1l, 1936, a work-supporter is pivotally mounted on the frame and is first operated to grip the work against the stapling arm and hold it suspended while a staple is driven therethrough. The work-supporter then yields to cause the ends of the staple-legs to engage Camming grooves in an anvil whereby to rock the legs into parallel relation to the crossbar to form a flat stitch.

ln accordance with the present invention the spring ior holding the stapling arm in raised position with respect to the base is made su'iciently rigid to resist its movement toward the work until after the staple-driver has been actuated to drive a staple. In other words, the spring for holding the stapling arm raised is more resistant than the spring for holding the staple-driver in raised position on the arm. After a staple has been driven the arm moves toward the work to engage the ends of the projecting legs of the staple with camming grooves on the base to cause the` legs to be rocked into parallel relation to the crossbar without deformation intermediate their ends. Another feature of the present invention is the provision of an anvil mounted to slide on the base and having separate sets of camming grooves to adapt the implement to apply a staple to the work with either a permanent stitch or a temporary pin-stitch. Y,

In its preferred form as herein illustrated the invention is embodied in a fastener-applying implement of the type shown and described in Maynard United States Patent No. 2,037,334, issued April 14, 1936. Suce it to state herein that the implement comprises a base 2, a stapling arm 3 pivotally mounted on the base and an actuating lever Ll pivotally mounted on the arm and connected to operate a staple-driver 5. The base E is preferably constructed of sheet-metal stamped or embossed to form a generally flat, rectangular top plate 6 bounded by a depending beveled flange l. the base 2 adjacent its rearward end is a hingeblock or mounting 8 for the stapling arm 3 formed with a hollow magazine for the staples s. The stapling arm 3 is pivotally mounted on a pin 9 carried by rearwardly extending ears I6 on the hinge-block 3 with its ends projecting laterally through the depending sides of an inverted U- shaped member l l attached to the bottom of the arm. IThe sides of the member l I also overlie the sides of the hinge-block 8 on the base to prevent lateral twisting of the arm 3 with respect to the base.

The stapling arm 3 comprises a U-shaped member Ill having an inverted channel-shaped core l5 secured therein for supporting U-shaped staples s straddled thereacross. The forward end of the core l5 projects beyond the forward end of the member I5 and is provided with laterally offset, depending side flanges i6 having laterally projecting latching lugs il thereon. A channelshaped member i8 is supported between the side walls of the member lll with its bottom wall i9 overlying the core to hold the staples in ,place` thereon. The forward end of the core l5 is closed Fastened to the top plate 6 of by a U-shaped gate 20 having a front wall 2|y which cooperates with the end of the core to provide a throat 22 therebetween and side walls 23 which overlie the sides of the core with notches 2t formed therein for cooperation with the lugs l'l. The gate 2i) is pivotally mounted on the member I8 by means of a pin 2 5 which extends transversely through oval slots 2G in the side walls of the member with its ends secured to the side walls 23 of the gate. Thus, the pin 25 may pivot on the member i8 to permit the front wall 2l of the gate 2li to be moved away from the end of the core l5 to open the magazine. Normally the gate is held in closed position as illustrated in Fig. 1 by the notches 2d in its side walls 23 yieldingly engaging with the lugs i'i on the depending flanges i6 of the core i5. Ahairpin-shaped spring 2l tensioned between the arm 3 and pivot-pin 25 retains the notches 24 in engagement with the lugs Il, The staples s in the magazine are advanced along the core I5 toward 'the throat 22 by means of a pusher 28 and spring 29 connected thereto.

The staple-driver 5 is mounted to reciprocate in the throat 22 at the forward end of the arm 3 and is operated by the lever d. The lever t is of inverted channel-shape having opposite sides 36 overlying the sides of the arm 3 and a front wall 3l overlying the forward end of the arm. The lever il is pivotally mounted on the arm 3 by means of a pin 38 extending transversely through the sides of the U-shaped member I8 and the sides 36 of the lever.. Mounted on the inside face of the front wall 3l of the lever d is a block 39 having a tongue di) which extends rearwardly through a suitable hole in the driver 5. The lever l is yieldingly held in raised position with respect to the arm 3, as illustrated in Fig. l, by means of a relatively weak hairpin spring lll. At its forward end the lever l has a pad ft2 to .adapt it to" be manually depressed against the action of the spring 4I. Pivotally mounted between the sides of the U-shaped member i3 on the arm .3l is an element 43 which serves the double function of vdogging the staples when the gate 20 is open and 45 l preventing a full return of the driver 5 until a full 'stroke has been completed, as more fully described in the Maynard patent referred to above. The arm 3 is also provided with a staple-supporter 4t which is mountedl for combined pivotal and longitudinal movement to hold the crossbar of a staple s being' driven against the bottom edge of l pressed with respect to the arm to` drive a staple s, the resilient means thereafter yielding to permit the arm to move toward the base. As herein illustrated, the means for holding the arm 3 elevated above the base 2 comprises a leaf-spring 5l) attached to the base 2 and a plunger 5I acting between thespring andthe under side of the arm, but it will be understood that other forms of yielding means may be provided as will appear to those skilled in the art. The leaf-spring 53 has one end attached to the under side ofthe top plate 6 of the base 2 by means of a screw ,B3-and extends rearwardly from its point of attachment. The plunger 5l has a head 56 which bears against the spring 5B below the top plate 6 and a shankportion 54 which projects upwardly through a suitable hole 55 in the top plate 6 of the base 2 with its end bearing against the under side of the member lli of the arm 3. Thus, the plunger 5l has its opposite ends bearing against the spring 59 and the under side 0f the arm 3 adjacent the rearward end thereof to yieldingly hold the arm raised with respect to the base 2. Ther spring 5) of the present invention differs' from springs heretofore used for a similar purpose in that it is made of such dimensions or of such material as to have a greater resistance than the spring di whereof to hold the arm 3 in raised position with respect to the base 2 until the driver 5 has been operated to drive a staple s.

Another feature of the present invention is the novel form of anvil 6i! which is slidably mounted on the base 2 of the implement to selectively aline one or the other of two separate sets of camming grooves tl and 52 with the driver 5. The anvil 5i) comp-rises a fiat plate which overlies the top plate 6 at the forward end of the base 2 and is provided with laterally eX- tending finger pieces 63 to facilitate sliding it from one to the other of its two positions. The earnining grooves il! and 62 are in the form of slots cut into the top face of the anvil 6@ and the two separate sets are spaced longitudinally theren of. The camming grooves El are adapted to rock the legs of a staple inwardly toward each other, the outer ends of the grooves being spaced apart a distance substantially equal to the distance between the staple legs. The bottoms of the cam.- ming grooves Bl are continuously curved from the top face of the anvil at their outer ends inwardly toward each other and terminate in a common apex Ell at the center. The camming grooves 62, on the other hand, are adapted to form atemporary pin-stitch by being arranged in longitudinally spaced. relationship with their inner ends spaced apart a distance substantially equal to the distance between the staple legs. The bottoms of the camming grooves 52 are continuously curved from the top face of the anvil at their inner ends laterally outwardly and terminate at the top face of the anvil at their outer ends.

Instead of curling the legs of a staple as it is being driven the camming grooves lil or 52 of the present invention act to rock the legs of the staple about axes having a fixed relation to their points of joinder with the crossbar of the staple without substantially deforming the legs intermediate their ends. Therefore by the term rook as used herein and in the appended claims is meant the swinging movement of the legs about axes which are relatively fixed in relation to the staple without substantial deformation intermediate the ends of the legs in contradistinction to the usual curled clinch caused by a continual deformation of the legs by the clincher-grooves while the staple is being driven.

The anvil till overlies a T-shaped slot in the top plate (i of the base 2, the slot being formed vby a relatively narrow portion E55 extending pending flange 68 at its rearward end of a width corresponding to the width of the narrow portion 55 of the slot. Thus, the relatively close t of `the flanges 68 and t!! in the slot-portions (it` and 65 holds the anvil @il against twisting movement on the base 2 while permitting relative longitudinal sliding movement thereof. The'arrangement of the T-shaped slot on the base 2 is such as to aline the. camming grooves 62 with the driver 5 when the depending flange 69 is in engagement with the rearward end of the slotportion 65 and to aline the camming grooves 6l with the driver when the flange @8 is in engagement with `the forward end of the slot-portion SS. The bottom of the anvil SEB is provided with a depending detent l@ having beveled sides which cooperate with the opposite sides of the bridge tl extending across the narrow portion of the T-shaped slot to detain the anvil lili in one or the other of its two operative positions.

The anvil Se is yieldingly held against the top plate Ei of the base 2 by means of a stud 'i4 which projects downwardly from the under side of the anvil through the narrow portion 65 of the T- shaped slot. A compression spring 15 mounted on the shank of the stud "24 acts between a head EB at the lower end of the stud and a washer Tl on the shank to press the latter against the bottom of the top plate t at opposite sides of the portion E5 of the slot, see Fig. 11. thus constitutes a removable self-contained unit which may be applied to the base 2 by sliding it rearwardly thereon while the washer l? is depressed against the action of the spring l5 by any suitable tool to cause the shank of the stud ton- K` enter the narrow portion 65 of the slot with the washer on the under side of the top plate 5 of the base. After the shank portion of the stud has entered the slot-portion 65 the depending flange 88 at its forward end engages the wider portion 6 of the slot. The spring 'l5 acting between the washer and the head l@ of the stud 3. A supply of staples s, preferably in the form of a stick, is then slid rearwardly onto the core l5 against the action of the pushery 28, the spring;`

29 yielding for this purpose. When released, the staples are held against movement outwardly of the magazine in the arm 3 by the element '53 until the gate 2S is rocked to its closed position to release the element. cally fed forwardly by the pusher 2&3 under the action. of the spring 29 to position the foremost staple in the throat 22. If a temporary pinstitch is to be formed the anvil i is slid rearwardly to position the camming grooves 62 in alinement with the driver 5 and when a permanent stitch is to be made the anvil is slid forwardly to position the camming grooves fil in alinement with the driver.

The work w is positioned in the opening between the anvil 5f? and the staple-applying mechanism on the arm 3 and the pad l2 at the forward end of the lever 3 is then depressed. Due to the resistance of the spring 50 acting on the arm 3 by means of the plunger 5l, the forward"4 The staples s are automati-V open the forward end of the magazine in the arm end of the arm is held raised position with respect to the base 2 until the driver 5 has been operated through a complete driving stroke to drive a staple s to pierce its legs through the work w in the manner illustrated in Figs. 2 and 5. Continued pressure on the lever 4 after the staple has been driven causes the spring 50 to yield and the forward end of the arm 3 to move' toward the anvil 60. The engagement of the ends of the legs of the staple s with the camming grooves 62 then causes them to be rocked outwardly without deformation intermediate their ends and the crossbar as illustrated in Fig. 6. This rocking movement of the legs of the staple s continues during the, movement of the arm 3 toward the work until a pin-stitch is formed in the manner illustrated in Fig. 7. Due to the alinement of the laterally projecting legs of the staple substantially with its crcssbar the stitch may be easily and quickly removed in the manner of withdrawing a pin without mutilating or tearing the work. When the lever 4 is released the springs ll and 50 act simultaneously to raise the lever and the driver 5 with respect to the arm 3 and to raise the arm With respect to the base 2.

When a permanent stitch is to be formed the anvil 60 is slid along the base 2 to aline the camming grooves 6I with the driver 5. To slide the anvil 60 the laterally extending nger-pieces 63 are grasped between the finger and thumb and drawn forwardly on the base 2. Due to the inclination of the depending detent 'l0 the anvil 60 is cammed upwardly against the action ofthe spring whereby it will ride over the bridge 6l during its forward movement until its depending flange 63 engages the end of the slot portion 66. The camming grooves Si are then alined with the driver 5 and the detent lil is engaged with the opposite side of the bridge 6l to yieldingly hold the anvil 6B in operative position on the base. With this adjustment the staple s is driven in the same way as explained above, the arm 3 being held in raised position with respect to the base 2 until the staple is driven and thereafter moved toward the work to engage the ends of the legs with the camming grooves 6l as illustrated in Fig. 9. Continued movement of the arm 3 with respect to the base 2 causes the legs of the staple to be rocked inwardly toward each other without deformation intermediate their ends and the crossbar to form a at permanent clinch.

It will be observed from the foregoing that the present invention provides a construction and arrangement of elements wherein the spring for holding the arm raised with respect to the base is more resistant than the spring for holding the driver in raised position on the arm whereby a staple may be driven through the work before its legs are clinched. It will also be observed that the arrangement is such as to provide for rocking the legs about Xed axes to form a fiat stitch instead of curling the legs during the driving of the staple. vention provides a'novel form oi anvil which is slidable along the base to adapt it to selectively adjust one or the other` of the spaced pairs of camming grooves in alinement with the driver whereby a ilat temporary pin-stitch or a permanent closed stitch may be obtained at the will of the operator.

While the device is herein illustrated as em? bodied in a preferred form of construction, it is to be understood that modifications may be made in the structure and arrangement of its parts It will be observed further that the in`v Ydisipar arm mounted on the base for movement toward .1

and away from the latter, a driver on the arm for applying staples fed thereto, a spring for holding the driver in raised position on the arm, and a second spring o f greater resistance than the first-mentioned spring acting on the arm spring operating to hold the arm raised with respect to the work. on the base until the driver has been actuated to drive a staple to penetrate its legs through the work and thereafter v yielding 1 to permit the arm to move toward the base.

2. In a device of the type indicated, a base, an arm pivotally mounted on the base for movement toward and away from the latter, a driver on the arm for applying staples fed thereto, a spring for holding the driver in raised position on the arm, a second springe;r greaterresistance than the first-mentioned spring acting on the arm rearwardly of the driver, said second-mentioned spring operating to hold the arm raised With re-` spect to the work on the ybase until the driver has been actuated to drive a staple to penetrate its legs through the work and thereafter yielding to permit the to move toward the base, and` camming means on the base adapted to be en` :l0 rearwardly of the driver, said second-mentioned( gaged by the ends of the projectingI legs of the staple to rock them into parallel relation to the crossbar of the staple without substantial deformation intermediate their ends to form a fiat stitch.

3. In a deviceof thetype indicated, a base, an e arm pivotally mounted on the base, a driver on the arm for applying staples fed thereto, a lever pivotally mounted on the arm and connected to operate the driver, a spring for holding the lever raised with respect to the arm, a second spring of greater resistance than the first-mentioned spring acting on the arm rearwardly of the driver to hold the arm raiseduntil the driver has been actuated to drive a staple to penetrate its legs through the work, and cam-slots on the base adapted to be engaged by the ends of the projecting legs of the staple to rock them into parallel relation to the crossbar of the staple without substantial deformation intermediate their ends to form a flat stitch.

Ll. In a device of the type indicated, a base, an arm mounted on the base to adapt it to be moved toward and away from the latter, stapling mecha.- nism carried by said arm including a stapledriver, a spring for holding the driver in raised position on said arm, a second spring of greater resistance than the iirst-mentioned spring acting on the arm rearwardly of the driver, said second-mentioned spring operating to hold the arm raised with respect to the Work on the base until a staple has been driven to penetrate its legs through the Work, and selective sets of camming grooves on said base for forming different types of stitches, said camming means being engaged by the ends of the projecting legs of the staple to rock them'into parallel relation to the crossbar of the staple without substantial deformation intermediate their ends.

5. In a fastener-applying implement, a base having a slot adjacent one end with a bridge extending across the slot, an arm mounted on the base to adapt it to be moved toward and away from the latter, staple-applying mechanism on the arm, an anvil slidable on the base and hav-5 ing separate sets of camming grooves for forming different types of stitches, said anvil overlying the slot in the base and having a detent intermediate its ends for cooperation with the opposite sides of the bridge and flanges at its opposite ends depending into the slot, and resilient means for yieldingly holding the anvil `on the base.

6. In a fastener-applying implement', a base having a T-shaped slot adjacentone end with a bridge extending across the slot intermediate the ends thereof, an `arm pivotally mounted on the base, staple-applying mechanism on'the arm, a removable anvil slidable on the base and having separate pairs of camming grooves for forming different types of stitches, said anvil overlying the T-shaped slot andha-ving va detent intermediate its ends for cooperation with the opposite sides of the bridge and depending anges at its ends cooperating With the ends of the slot to position one or the other of the pairs of camming grooves in alinement with the staple-applying mechanism on the arm, a stud depending from the anvil through the slot in the base, vand a spring acting between the stud and the bottom of the base to yieldingly hold the anvil in place on the base. e

'7. In a device of the type indicated, an anvil adapted to support the Work resting directl;7 thereupon, fastener-applying means mounted for movement toward and away from the anvil, a driver incorporated in the fastener-applying means for driving fasteners fed thereto, a spring for holding the driver in raised position with respect to the fastener-applying means, a second spring of greater resistance than the rst-mentioned spring for holding the fastener-applying means raised with respect to the anvil, said second-mentioned spring operating to hold the fastener-applying means raised with respect to the Work on the anvil until the driver has been actuated to drive a fastener to penetrate its legs through the Work and thereafter yielding to permit the fastener-applying means to move toward the anvil.v

ARTHUR H. MAYNA-RD. JOSEPH M. GAMBAO. 

